The present invention relates to an improved high performance torque motor which may have a relatively small size, and/or a relatively high torque, and/or large angular displacements when compared to conventional torque motors.
By way of background, designers of torque motors attempt to maximize torque and displacement output with minimum electrical input, size and weight. By way of further background, conventional torque motors include a frame, magnets mounted on the frame, an armature, and a coil wound around the armature, with the coil either being rigidly attached to the frame or mounted on the armature. In these motors there is limited space for the coil. Furthermore, where the armature is mounted on the frame, the size of the coil must be designed with clearance around the armature to allow for armature motion. Also, the area of the air gaps between the frame and the armature is limited by the size of the coil window, that is, the opening in the coil in which the central portion of the armature is located. Furthermore, torque motor performance is limited by the size and type of the permanent magnet. Additionally, there is a relatively great loss of magnetic flux because of leakage between the various parts and because of the various bends in the frame through which the magnetic lines of force from the magnets have to pass. In other words, losses are due to the fact that the magnets in a conventional torque motor are spaced relatively far from the air gaps. In addition, the greater the loss, the greater is the volume of coils and power required to compensate for the loss, which in turn increases the size of conventional torque motors for producing a given output.